Legacy communications systems such as the Personal Handy-phone System (PHS) are configured to be simple and low cost. Upgrading of these systems employing newer available technologies while maintaining the basic simplicity allowed by the PHS system specifications provides very cost effective yet powerful systems with improved signal performance. The availability of Digital Signal Processors (DSP) as a newly cost effective basic building block for the system provides an enhanced basic capability for both the modulation and transmitter paths as well as the demodulation and receiver paths.
Elimination of multipliers limits the hardware requirements for the base band integrated circuit (BBIC) for the transmission path in advanced PHS systems. It is therefore desirable to provide a digital up-sampling converter with a Square Root Raised Cosine (SRRC) filter capability for pulse shaping of the base band signal without the use of multipliers.